Tumbling mill trunnion shaft mounting



Dec. 13, 1966 J. J. FISCHER 3,291,459

TUMBLING MILL TRUNNION SHAFT MOUNTING Filed May 15, 1965 2 Sheets-Sheet 1 INVENTOR. JOHN J. FISCHER A T TORNEYS Dec. 13, 1966 J. J. FISCHER 3,

TUMBLING MILL TRUNNION SHAFT MOUNTING Filed May 13, 1965 2 Sheets-Sheet 2 INVENTOR. JOHN \J. F/5 CHER ATTORNEYS United States Patent 3,291,459 TUMBLING MILL TRUNNION SHAFT MOUNTING John 31. Fischer, East Stroudsburg, Pa., assignor to The Patterson-Kelly Co., 11112., East Stroudsburg, Pa. Filed May 13, 1965, Ser. No. 455,414 2 Claims. (Cl. 25989) This invention relates to materials mixing and blending machines, and more particularly to the so-called tumbling barrel type mill comprising a closed box or barrel-like container trunnion-mounted to rotate for mixing the mill contents.

Whereas tumbling barrel type mills typically comprise variously shaped drum-like containers with stub shafts extending diametrically therefrom and attached thereto by various reinforcing devices for trunnion mounting purposes, it is a primary object of the present invention to provide an improved trunnion shaft mounting system for such mill containers, featuring an integrated shell and trunnion shaft construction of novel form.

A more specific object of the invention is to provide an improved construction as aforesaid whereby to reduce the bending moments on the structural portions interconnecting the trunnion shafts and the container body or shell.

Still another object is to provide an improved trunnion shaft mounting and shell load distribution arrangement in integrally constructed mill shell and trunnion shaft systems, whereby substantial economies of manufacture as well as improved shell reinforcement results are obtained.

Another object is to provide an improved construction as aforesaid which is structurally simple and easy and inexpensive to fabricate, and which is particularly advantageous when embodied in large shell mills, in that the trunnion shaft loads are levered and counter-levered into the mill shell structure in improved manner.

Another object is to provide an improved construction as aforesaid wherein the mill shell and trunnion shaft bracing devices function also to aid in subjecting the mill contents to an improved mixing and/or blending action.

Other objects and advantages of the invention will appear from the specification hereinafter and the accompanying drawing wherein:

FIG. 1 is a side elevational view, with portions in section, illustrating construction by way of example, of a double cone type blending mill embodying the trunnion shaft mounting arrangement of the invention; and

FIG. 2 is a sectional view taken as indicated by line 22 of FIG. 1.

As shown herein, the invention is embodied in a blending mill comprising generally a materials tumbling container or shell of the so-called double cone type. More specifically the container shown herein comprises a cylindrically shaped central body portion 12 subtended in boh directions by frusto-conical shaped shell portions 1414 terminating at their apex ends in materials loadingunloading portals and detachable closures therefor as indicated at 16, 18. The shell parts are integrated by Welding as indicated at 19, 20, thus providing the basic double-cone type shell construction. The stub shafts for mounting the shell on trunnion bearings are illustrated at 22, 24; the shaft 24 being fitted with a driving or bull gear wheel as indicated at 25.

The present invention features an improved trunnion shaft mounting system comprising a cone-shaped bafile member 26 welded as indicated at 27 to the inwardly extending end portion of each trunnion shaft, and at 27a to the shell portions 12, 14, 14. The shell body portion 12 is apertured as illustrated to accommodate extensions therethrough of said shafts which are each externally embraced by circular reinforcing plates which are welded to the shafts and to the shell part 12. The plate encircling the shaft 24 provides a convenient base upon which to mount the hub plate 28 of the driving gear 25, as by means of bolts 29. For this purpose the plate is preferably shaped as shown at 30 to conform at its inner face to the curve of the shell member 12 and to present a flat outer face against which the hub of the drive gear rests. The plate encircling the other shaft 22, on the other hand may comprise simply a heavy washer-like member 32 bent to conform to the outer curvature of the shell member 12. Both plates are Welded to the shell and to their respective shafts as indicated at 33, 34.

In fabricating the structure of the invention, the following sequence of operative steps may be conveniently followed. Shell parts 1414 are first welded to shell part 12 along lines 19-20 from either inside or outside of the structure. Openings to receive the shafts may then be cut through the shell part 12 and the shafts inserted and tack-welded in approximate positions. The structure is then set up with the shafts resting on the pedestals which are to go with the mill, thereby bringing the shafts into proper alignment and attitudes relative to the shell. The cones 26-26 are then welded in place from inside of the shell, both to the shell and to the shafts. The plates 30, 32 are then welded in position, both to the shell and to the shafts, thus completing the shaft-shell assembly.

Thus, it will be apparent that each stub shaft is mounted relative to the mill shell structure by means of a conical box-truss type system, featuring diagonally braced connection arrangement between the trunnion shafts and the shell, whereby the bending loads on the shafts are carried into the mill shell structure in improved manner. The c-onically shaped members 26-26 are of course extremely rigid per se and therefore most effective as shaft bracing and shell reinforcing members. Also, the cone members 26, 26 function as baffle devices as the mill rotates, whereby the materials being mixed therein are deflected laterally by the cones incidental to tumbling of the material. Furthermore, the cones blank off the extreme end portions of the mill interior which usually provide poor flow pocket areas in such mills.

It will be appreciated that by virtue of the compact structural arrangement of the parts as illustrated and described hereinabove, the trunnion bearings for support of the mill may be positioned immediately adjacent and close into the sides of the mill shell, thereby minimizing the bending moments imposed upon the shafts. Also, that the cones 26-26 provide against the inner ends of the shafts an optimized counter-lever system interiorly of the shell, so disposed and arranged as to not only occupy otherwise unimportant portions of the shell interior, but also to function as material counter-flow bafile devices.

Although only one specific form of the invention has been shown and described in detail herein, it will of course be understood that various changes may be made therein without departing from the spirit of the invention or the scope of the following claims.

I claim:

1. A materials mixing mill comprising, in combination,

a shell having a cylindrical central body portion and a pair of frusto-conical shell portions having their bases joined to opposite ends of said central body portion,

a pair of stub shafts fixed to said central body portion at diametrically opposite points thereon and substantially midway between said opposite ends of the central body portion, said stub shafts being axially aligned and each having an inner end portion projecting into said shell and an outer end portion projecting outwardly from said shell,

means for rotating said shell about a horizontal axis defined by the axes of said stub shafts,

a cone-shaped bafile member for each dead space region of the central body portion surrounding the point of intersection of said horizontal axis with the shell, each bafile member having its apex end portion fixed to said inner end portion of an associated stub shaft adjacent the inner extremity thereof and each batfle member having a base of a diameter substantially equal to the length between said opposite ends of the central body portion, each such base of the bafile members being circumferentially fixed to the inner surface of the shell not only to rigidly support a respective stub shaft but also to block and deflect material from said dead space regions of the shell.

2. The materials mixing mill according to claim 1 wherein one of said stub shafts is provided with a circular plate surrounding the outer end of said one stub relation to said plate.

References Cited by the Examiner UNITED STATES PATENTS Rybeck 259177 Longenecker 259175 Saxon M 259-81 Lendved 259177 Muench 25981 WALTER A. SCHEEL, Primary Examiner.

R. W. JENKINS, Assistant Examiner. 

1. A MATERIALS MIXING MILL COMPRISING, IN COMBINATION, A SHELL HAVING A CYLINDRCIAL CENTRAL BODY PORTION AND A A PAIR OF FRUSTO-CONCIAL SHELL PORTIONS HAVING THEIR BASES JOINED TO OPPOSITE ENDS OF SAID CENTRAL BODY PORTION, A PAIR OF STUB SHAFTS FIXED TO SAID CENTRAL BODY PORTION AT DIAMETRICALLY OPPOSITE POINT THEREON AND SUBSTANTIALLY MIDWAY BETWEEN SAID OPPOSITE ENDS OF THE CENTRAL BODY PORTION, SAID STUD SHAFT BEING AXIALLY ALIGNED AND EACH HAVING AN INNER END PORTION JECTING INTO SAID SHELL AND AN OUTER END PORTION PROJECTING OUTWARDLY FORM AND SHELL, MEANS FOR ROTATING SAID SHELL ABOUT A HORIZONTAL AXIS DEFINED BY THE AXES OF SAID STUB SHAFT, A CONE-SHAPED BAFFLE MEMBER FOR EACH DEAD SPAE REGION OF THE CENTRAL BODY PORTION SURROUNDING THE POINT OF INTERSECTION OF SAID HORIZONTAL AXIS WITH THE SHELL, EACH BAFFLE MEMBER HAVING ITS APEX END PORTION FIXED TO SAID INNER END PORTION OF AN ASSOCIATED STUB SHAFT ADJACENT THE INNER EXTREMITY THEREOF AND EACH BAFFLE MEMBER HAVING A BASE OF A DIAMETER SUBSTANTIALLY EQUAL TO THE LENGTH BETWEEN SAID OPPOSITE ENDS OF THE CENTRAL BODY PORTION, EACH SUCH BASE OF THE BAFFLE MEMBERS BEING CIRCUMFERENTIALLY FIXED TO THE INNER SURFACE OF THE SHELL NOT ONLY TO RIGIDLY SUPPORT A RESPECTIVE STUB SHAFT BUT ALSO TO BLOCK AND DEFLECT MATERIAL FROM SAID DEAD SPACE REGIONS OF THE SHELL. 